Left Cardiac Chambers Reverse Remodeling after Percutaneous Mitral Valve Repair with the MitraClip System

Abstract

Successful mitral valve surgical repair, decreasing volume overload, has been shown to provide reverse left ventricular (LV) and/or left atrial remodeling in most patients. Percutaneous mitral valve repair with the MitraClip system (Abbott, Abbott Park, IL) has been associated with favorable clinical outcomes in patients with mitral regurgitation at high risk of surgery. However, specific data on left cardiac chambers reverse remodeling after such procedures are limited. This was a prospective observational study of consecutive patients at high risk of surgery, with moderate-to-severe or severe mitral regurgitation undergoing MitraClip system implantation. Follow-up echocardiography was performed at 6 months. The evaluated parameters were the LV end-diastolic and end-systolic volume indexes, LV sphericity index, LV ejection fraction, and left atrial volume index. Reverse LV remodeling was defined as a decrease of 10% in the LV end-diastolic volume index. The study population included 44 patients: 14 with degenerative and 30 with functional mitral regurgitation. At 6 months of follow-up, significant reductions in the median and interquartile range of the sphericity index (from 0.57 [interquartile range 0.54-0.62] to 0.54 [interquartile range 0.50-0.58]; P < .001), LV end-diastolic volume index (from 79.4 mL/m(2) [interquartile range 63.0-102.2] to 60.7 mL/m(2) [50.8-84.4]; P < .001), and LV end-systolic volume index (from 49.3 mL/m(2) [interquartile range 28.2-70.5] to 28.9 mL/m(2) [interquartile range 22.2-55.8]; P < .001) were observed. The LV ejection fraction improved significantly (from 38.0% [interquartile range 30.0-55.0%] to 46.0% [interquartile range 35.0-58.0%]; P < .001) from baseline to 6 months. Minor differences in the left atrial volume index were observed. Reverse remodeling, according to the specified definition, was observed in 77.3% of the patients. The present study reports positive LV reshape effects after mitral valve repair with the MitraClip system, showing significant improvements in LV size and function.